21939015157 has 2 divisors, whose sum is σ = 21939015158. Its totient is φ = 21939015156.

The previous prime is 21939015149. The next prime is 21939015167. The reversal of 21939015157 is 75151093912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19454391441 + 2484623716 = 139479^2 + 49846^2 .

It is a cyclic number.

It is not a de Polignac number, because 21939015157 - 2³ = 21939015149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21939015167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10969507578 + 10969507579.

It is an arithmetic number, because the mean of its divisors is an integer number (10969507579).

Almost surely, 2^21939015157 is an apocalyptic number.

It is an amenable number.

21939015157 is a deficient number, since it is larger than the sum of its proper divisors (1).

21939015157 is an equidigital number, since it uses as much as digits as its factorization.

21939015157 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 85050, while the sum is 43.

The spelling of 21939015157 in words is "twenty-one billion, nine hundred thirty-nine million, fifteen thousand, one hundred fifty-seven".